1. Field of the Invention
The present invention relates to a electronic apparatus and a method of cooling the electronic apparatus, which are particularly favorable for a notebook personal computer and the like.
2. Description of the Related Art
A notebook personal computer comprises a housing in which a cooling fan module is provided. The cooling fan module cools the entire system of the computer including a CPU. The compute also comprises a temperature sensing IC for sensing the temperature of the CPU. When the temperature of the CPU exceeds a preset temperature, the IC supplies a sensing signal to the cooling fan to rotate the cooling fan and thus cool the entire system of the computer including the CPU.
Jpn. Pat. Appln. KOKAI Publication No. 10-307648 discloses a method of controlling the rotation speed of a single fan module based on information obtained from temperature sensors located in different positions as well as a position corresponding to a CPU in a notebook personal computer.
In the computer of the Publication, the temperature sensors have their own temperature values in advance. When the temperature actually sensed by at least one temperature sensor is not lower than the preset temperature value, the fan module rotates to cool the entire system of the personal computer including the CPU.
Another system including a plurality of cooling fan modules to increase the volume of cooled air and the number of main cooling points is proposed. This system is similar to the control method of the above Publication in that the cooling fan modules turn on/off together.
As described above, conventionally, the entire system of a personal computer including a CPU is cooled by turning on/off cooling fan modules or controlling the rotation speed of the cooling fan modules.
Assume that a heating member such as a CPU that operates at high speed and generates a large amount of heat is loaded into a notebook personal computer whose cooling space is limited. It is very likely that the cooling fan modules will have to rotate at all times. This is not realistic in view of power consumption and noise.